Finding the Fourth Proportional to 99.55, 149.37 and 72.71

Step by Step Solution

1. Step 1: Write the proportion equation
   99.55 : 149.37 = 72.71 : x
2. Step 2: Convert to fraction form
   99.55/149.37 = 72.71/x
3. Step 3: Cross multiply
   99.55x = 149.37 × 72.71
4. Step 4: Simplify right side
   99.55x = 10,860.69
5. Step 5: Solve for x
   x = 10,860.69/99.55
6. Step 6: Final answer
   x = 109.10